Universally adjustable dial indicator holder



May 6, 1969 N. PARAPETTI 3,442,473

UNIVERSALLY ADJUSTABLE DIAL INDICATOR HOLDER Filed June 20, 1967 Pie. '1I 1 INVENTOR N\COLAS PARAPETT\ ATTORNEY United States Patent 3,442,478UNIVERSALLY ADJUSTABLE DIAL INDICATOR HOLDER Nicolas Parapetti, 615, N.1st St., Rockford, Ill. 61104 Filed June 20, 1967, Ser. No. 647,432 Int.Cl. A47f /00; A47h 1/10 US. Cl. 248-284 14 Claims ABSTRACT OF THEDISCLOSURE This universally adjustable dial indicator holder comprises aC-clamp easily applicable from either side to a spindle on a verticalmilling, boring, or grinding machine without disturbing the tooling onthe spindle at given setting thereof, the clamp carrying on one sidethereof a first swivel bolt joint with respect to which a rod isextensibly or rotatably adjustably clamped, the rod having swivelled onits outer end a second swivel bolt on which one end of a link isswivelled, the link carrying on its other end a third swivel boltadjustably supporting a dial indicator. The latter mounting may be of aform utilizing a dovetail sliding connection for endwise adjustabilityof the dial test indicator relative to the swivel. Each of the threeswivel bolts has a manually adjustable nut thereon for tightening aspring tensioned friction joint, whereby the articulated assembly isadapted for holding the dial indicator reliably in practically anyposition of adjustment.

This invention relates to a device for mounting a dial indicator of thetype commonly known as a dial test indicator.

More particularly, my invention relates to a clamp and its articulatedassembly as an attachment for holding such an indicator in any desiredposition. It is also adapted for other applications, but has beendesigned principally for use on vertical milling, boring, and grindingmachines.

In the general practice in tool rooms and production shops theindicators and their attachments are mounted in a collet or chuck thatfits into the machine spindle. This operation obviously requires removalof the working tool from the collet or chuck (a time consuming step,particularly when the collets internal diameter does not fit theindicator mounting means), tightening the supporting means of theindicator, doing the reading, and then removing the indicator andremounting the working tools necessary for the planned operation.Failure to notice then, when removing such working tools, if these toolswere preset for diameter or depth, means that the entire setup time islost for there is always a possibility the tool cannot be relocatedexactly in the same position as it was prior to the indicator reading.

The present device, the object of this invention, does not requiredisturbing the working tool, for the device can readily be clamped onthe machine quill, and thus bypass the Working tool, saving all the timepreviously lost.

The clamp includes at least two bearing points properly spaced on a Vand a pressure screw symmetrically arranged opposite to those bearings,thereby securing the required rigidity of the mounting. A plastic swivelshoe on the screw avoids marring the outside diameter of the quill. Anextension of this clamp provides the articulation for the adjustable rodthat holds at its other end a second articulation that holds a link thatalso at its other end carries a third articulation that mounts theindicators shank or indicator mounting dovetail. These threearticulations, as shown in the drawing, are each frictionally mounted bymeans of a compressible spring washer 3,442,478 Patented May 6, 1969applying pressure on plastic bearings. The pressure is adjustable to getthe desired stiffness in the assembly and is not affected by thepivoting of these three articulations.

This assembly is very flexible and, after tightening of the clamp,permits the indicator to be brought into the desired reading positionwhere it can cover a broad area of surfaces to be checked. Theconstruction of this device also allows the indicator to be maintainedon the center line of the spindle.

The types of readings performed by the indicator are (1) concentricitypositioning of the work relative to the spindle center line, (2)alignment of the edge of the work with the longitudinal or transversemovement of the machine tables, and (3) checking the perpendiculan'ty ofthe spindle center line relative to the surface of the table.

The above mentioned general objects of my invention are attained by thedevice illustrated in the accompanying drawing, wherein similarreference numerals or letters are applied to corresponding parts, andwherein:

FIG. 1 is an exploded side elevational view of the boring machine;

FIG. 2 is a section of the clamp and articulation D on line 2-2 of FIG.1;

FIG. 3 is a section of the attachment through articulations E and F ofFIG. 1, on line 33 of FIG. 1;

FIG. 4 is a view like FIG. 3 but a modification of the clampingmechanism at articulation for mounting an indicator by its bodydovetail;

FIG. 5 is a side elevation of FIG. 4;

FIG. 6 is a plan view of one of the washers of articulation D, taken online 66 of FIG. 2;

FIG. 7 is a view like FIG. 2 showing a modification of articulation D,and

FIG. 8 is a plan view of one of the tapered split friction washers,taken on line 88 of FIG. 7.

The dial indicator 12 shown in full lines in FIG. 1 in position Aillustrates how the center line of a bore 14 in work W can be checkedfor concentricity relative to the center line or axis of spindle 3. Forthis the spindle 3, on which the clamp 6 is mounted, will be rotatedslowly through 360 and the side of the bore will be checked by slidingengagement therein of the feeler contact 13 of the indicator. Position Bshows how the edge 15 of the Work W mounted on the table 16 of themachine can be checked for parallelism relative to the movements of thetable 16 of the machine. Position C shows how the surface of the machinetable 16 can be checked for squareness with the spindle axis or centerline by having the machine table left stationary and the spindle lockedin its elevation with respect to the table, while slowly rotating thespindle (with my device mounted on it) through 360. The indi cator point13 will sweep the table and check to determine if its surface is exactlyon a plane parallel to the plane generated by the rotation of thespindle.

On the left side of FIG. 1 the machine table 16 shown in dotted lines isrepresented at a different level from that same table shown in fulllines on the right side of FIG. 1, this being only for convenience ofillustration. FIG. 1 shows also two different types of working toolsmounted on the spindle 3 of the machine. The left side shows a cutter 4and the right side a boring tool 5, this serving to illustrate thatthese tools do not interfere with the mounting of the indicator holder6, and consequently when either of these tools is in use it can be leftin place.

Referring to FIG. 1, a portion of the frame of the machine is shown at 1with a quill 2 projecting downwardly therefrom, along with a spindle 3in coaxial relationship to the quill and carrying a cutter 4 by means ofits tapered shank indicated largely in dotted lines, a half portion of aboring tool being also indicated in dotted lines at to indicateinterchangeability of tools when the clamp 6 of the universal indicatorholder of my invention is in use, the clamp 6 being generally C- shapedas appears in FIG. 2 and therefore readily applicable to the spindle 3from either side while any tool, as shown at 4 or 5, is in place in thespindle. The clamp 6 is fastened by tightening the screw 7 against oneside of the spindle, clamping pressure being applied by the shoe 8,which is threaded tightly onto the screw to the jam point and preferablyis equipped with a swivelled nylon protective pad 9 fitting over theshoe and having non-marring contact with the spindle on thediametrically opposite side from the two fiat bearing surfaces 17 thatare provided in relieved relationship to the inner diameter of that sideof the C-clamp and are spaced approximately 60 apart as shown, 30 onopposite sides of the center line of the screw, to provide three-pointbearing contact between the spindle and the clamp 6 when the screw 7 istightened. A third flat bearing surface may be provided at the 90position as shown, to bear on the spindle 3 the same as the othersurfaces 17 and make for still greater rigidity of the clamp 6. When asmaller diameter spindle 3 is encountered, only the first two bearingsurfaces 17 will contact the spindle.

The first of three articulations, D, E, and F, is provided on that sideof clamp 6 opposite the screw 7 and has an adjustable radius orextension rod 10 extending therefrom in the same vertical plane withscrew 7, as shown in FIG. 2, to the second articulation E, rod 10 aswill soon appear being slidable endwise with respect to articulations Dand E for a shorter or longer radius, the construction also permittingturning of articulation E about rod 10 as an axis or turning of rod 10relative to articulation D. The rod 10 may be longer as seen at 10' inFIG. 1, to provide as long a radius of operation as needed. A fiat link11 interconnects articulations E and F, between the outer end of rod '10or 10' and the dial indicator 12.

Referring next to the left side of FIG. 2, boss 24 projects from theclamp 6 and constitutes the bearing for the transversely disposed metalswivel bolt 18, which serves as the axis of the first of the threearticulations shown at D in addition to providing part of the means forclamping the extension rod 10 in its adjusted angular and endwiserelationship to articulation D. A fiat nylon washer 23 slips over thethreaded D-section end of bolt 18 for abutment with an arched springmetal washer 22 disposed between it and another flat nylon washer 21 forcompression of the spring washer to the desired extent by the manualtightening of knurled nut 19 relative to the bolt 18 to provide thedesired amount of frictional resistance to turning of bolt 18, and, atthe same time, provide a similar friction hold against slippage of theend of extension rod 10, which passes through diametrically opposedholes in the metal sleeve 26 that bears against a shouldered nylonwasher 25 abutting the opposite side of boss 24 from washer 23, the rod10 passing through a cross-hole 27 in the enlarged cylindrical head end28 of bolt 18 that fits inside sleeve 26. The compressible spring washer22 may be a Belleville type spring washer. A key-way 29 provided in thethreaded D section end of bolt 18 slidably receives a key projection onwasher 21, as clearly appears in FIG. 2, so that the nut and washer turnwith the bolt 18 and there is no danger of the nut loosening by reasonof the bolt being turned in the adjustment of the indicator to a desiredposition.

The construction of the two other articulations, E and F, is closelysimilar, as seen in FIG. 3, and corresponding parts have therefore beencorrespondingly numbered. The swivel bolt 18 is shorter than bolt 18,due to the diflerence in thickness of link 11 in relation to boss 24.Bolt 18" has no need for an enlarged cylindrical head 28 thereon, buthas a fiat head 30 on its outer end to retain the sleeve 31 before theshank 32 of the indicator 12 is inserted in the registering holes inbolt 18" and sleeve 31 for mounting the indicator 12 thereon.

.4 Referring to FIGS. 4 and 5, these show a modification of the clampingmeans in articulation F for mounting an indicator by its dovetail 33,one side of which is engaged in a half-dovetail groove 34, the otherhalf 35 of which is provided in the D-shaped head 36 provided on the endof swivel bolt 18a. The D-shaped head 36 cooperates with a projection 37on the end of the metal sleeve 38 to hold the two parts against turningwith respect to one another in the same way as if the shank 32 on theindicator 12 were inserted through the registering holes in the bolt 18aand sleeve 38 indicated at 39. The holes 39 to receive the shank 32 arealways kept in register by virtue of the way the D-shaped head 36cooperates with the projection 37 on the sleeve 38.

FIGS. 7 and 8 show another modification designed to give greaterrigidity, in which the first articulation D on bearing boss 24 has itsswivel bolt 18b extending loosely through a longitudinal bore in theboss and supported in tapered nylon bearing bushings 40 fitting intapered hearing openings in the opposite ends of the bore in the boss,the bushings being split, as seen at 42 in FIG. 8, to clamp the boltfrictionally, more or less firmly depending upon the tightness ofadjustment of nut 19 compressing the spring washer 22. The head 28' hasthe extension rod 10 or 10 extending freely through a cross-bore thereinand clamped in adjusted position by a set screw 41.

In operation, assuming that all of the nuts 19 on the swivel bolts inthe three articulations, D (or D), E, and F, have been tightenedproperly, the operator can adjust the articulated assembly of the holderrelative to the clamp 6 to set the indicator 12 with its contact 13 inproper relationship to the work with full confidence that the indicatorwill not shift its position during the taking of a reading, regardlessof which one of the three positions illustrated in FIG. 1 is used, orany other position. Naturally if, in order to get the indicator 12 in aparticular relationship to the work, it becomes necessary to shorten orlengthen the operating radius of rod 10, then one or both of the nuts 19on the swivel bolts at articulations D and E must first be loosened topermit the change in effective length of the rod (or substitution of alonger rod) and then retightened to restore the previous setting forfrictional resistance to movement of the parts relative to one another.The fact that the clamp 6 can be applied to the spindle 3 from eitherside without disturbing the cutter 4 or 5 prior to taking readings withthe indicator is a most important advantage, and, of course, the clampcan be removed again after taking the readings, with equal facility. Inthat way the operator loses no time and does not disturb whateverprevious work may have been done for setup purposes, as previouslymentioned.

It is believed the foregoing description conveys a good understanding ofthe objects and advantages of my invention.

I claim:

1. For use on the spindle of a machine tool behind and independent ofany tooling carried by and extending from said spindle, a universallyadjustable holder for a dial indicator comprising a C-clamp applied fromeither side of and adapted to be clamped to the spindle in a planenormal to the axis of rotation thereof and having a bearing projectingtherefrom, a first swivel bolt swivelled in said bearing and carryingclamping means thereon on one end, a cylindrical radius rod mounted atone end in said clamp means for swivel and endwise adjustability, a nutthreaded on the other end of said bolt adjustable to vary thecompression of spring means compressing friction washer means on thebolt between the bearing and said nut resisting turning of the bolt, alink substantially in parallel relation to said radius rod adapted tosupport the dial indicator on one end and adapted to be supported at itsother end on the outer end of said radius rod for swivel and endwiseadjustability relative thereto, a second swivel bolt pivotallyconnecting one end of the link with the outer end of said radius rod, athird swivel bolt in para1- lel relation to the second bolt forpivotally connecting the other end of said link to the dial indicator,said second and third swivel bolts both having clamp means on one endthereof, one of said clamp means adapted for receiving a portion of adial indicator to mount the same thereon, and the other of said clampmeans receiving the outer end of the aforementioned radius rod withfreedom for swivel and endwise adjustability relative thereto, and a nutthreaded on the other end of each of said bolts adjustable to vary thecompression of spring means compressing friction washer means on thebolts resisting turning thereof.

2. A structure as set forth in claim 1, wherein one of the frictionwashers next to the nut on each of said swivel bolts is keyed to theswivel bolt so that these washers turn with the' bolts and nuts in theswivel adjustments, reducing likelihood of any of the nuts loosening andrequiring readjustment.

3. A structure as set forth in claim 1, wherein the third swivel bolt onwhich the dial indicator is mounted has a head provided thereonretaining a sleeve and a friction washer between the head and the link,the rod and sleeve having registering holes provided therein throughwhich a stem on the dial indicator is extensible for clamping when thenut on the other end of the swivel bolt is tightened for spring loadingof the friction washer means.

4. A structure as set forth in claim 1 wherein the first swivel bolt hasa head provided thereon inside a sleeve, the sleeve bearing on afriction washer between it and the bearing, the head and sleeve havingregistering holes provided therein through which one end portion of theradius rod extends and is adjustable endwise and rotatably and isclamped when the nut on the remote end of said bolt is tightened forspring loading of the friction washer means.

5. A structure as set forth in claim 1, wherein the second swivel boltin the connection between the radius rod and the link has a head thereoninside a sleeve, the sleeve bearing on a friction washer between it andthe link, the head and sleeve having registering holes provided thereinthrough which the outer end of the radius rod extends for endwise androtary adjustability and is clamped by the tightening of the nut on theremote end of the bolt for spring loading of the friction washer means.

6. A structure as set forth in claim 1, wherein the swivel bolt on whichthe indicator is mounted has a head provided thereon retaining a sleeveon the bolt and a friction washer between the sleeve and the link, thebolt and sleeve having registering holes provided therein adapted toreceive a stem provided on the dial indicator, the sleeve having oneside of a dove-tail groove provided thereon on one side thereof, theother side portion of the dove-tail groove being provided in the head onsaid bolt, the dial indicator having a dove-tail portion thereon forreception in the dove-tail groove provided in said sleeve and head foradjustably clamping the dial indicator in a selected position ofadjustment relative to said swivel bolt and link when the nut istightened on the remote end of the bolt for spring loading of thefriction washer means.

7. A structure as set forth in claim 1, wherein the swivel bolt on whichthe indicator is mounted has a head provided thereon retaining a sleeveon the bolt and a friction washer between the sleeve and the link, thebolt and sleeve having registering holes provided therein adapted toreceive a stern provided on the dial indicator, the sleeve having oneside of a dove-tail groove provided thereon on one side thereof, theother side portion of the dove-tail groove being provided in the head onsaid bolt, the dial indicator having a dove-tail portion thereon forreception in the dove-tail groove provided in said sleeve and head foradjustably clamping the dial indicator in a selected position ofadjustment relative to said swivel bolt and link when the nut istightened on the remote end of the bolt for spring loading of thefriction washer means, the structure including means holding the swivelbolt and sleeve against turning relative to one another whereby tomaintain the holes for the stem in register and also maintain the twosides of the dove-tail groove in proper register with respect to oneanother.

8. A structure as set forth in claim 1, wherein the swivel bolt on whichthe indicator is mounted has a head provided thereon retaining a sleeveon the bolt and a friction washer between the sleeve and the link, thebolt and sleeve having registering holes provided therein adapted toreceive a stem provided on the dial indicator, the sleeve having oneside of a dove-tail groove provided thereon on one side thereof, theother side portion of the dove-tail groove being provided in the head onsaid bolt, the dial indicator having a dove-tail portion thereon forreception in the dove-tail groove provided in said sleeve and head foradjustably clamping the dial indicator in a selected position ofadjustment relative to said swivel bolt and link when the nut istightened on the remote end of the bolt for spring loading of thefriction washer means, one side of the head being fiat and the sleevehaving a projection thereon disposed in abutment with the flat side ofthe head to hold the swivel bolt and sleeve against turning relative toone another, thereby maintaining registration of the holes in the sleeveand bolt and proper register of the two sides of the dove-tail groove.

9. A structure as set forth in claim 1, wherein the first swivel bolthas a head provided thereon in which a diametrically extending hole isprovided slidably and rotataably adjustably receiving one end of saidradius rod, there being means securing the rod in adjusted relationshipto said head, the head bearing against a friction washer between it andthe bearing on the clamp, said washer being clamped when the nut on theremote end of said bolt is tightened for spring loading of the frictionwasher means.

10. A structure as set forth in claim 1, wherein the first swivel boltis mountedin the bearing projection on the C-clamp in split taperedbearing bushings entered in tapered bearings in the bearing projection,whereby the bushing are compressible on the bolt to eliminate play andgive added friction when the nut on the bolt is tightened for springloading of the friction washer means.

11. A structure as set forth in claim 1, wherein the C-clamp has aclamping screw on one end of the C- clamp, the bearing projection beingprovided on the other end of the C-clamp, the radius rod swivelledrelative to said bearing being movable in coplanar relationship to saidclamping screw in a plane normal to the plane of said C-clamp.

12. A device as set forth in claim 1 wherein the C- clamp has a clampingscrew threaded in one end of the C-frame of said clamp and has twoinwardly embossed flat bearing surfaces on the inner circumference ofthe other end of the C-frame spaced approximately 30 on Opposite sidesof a center line extended from said screw, these surfaces being tangentto a circle of a predetermined radius for a spindle small enough toenter between said surfaces and said screw for clamping engagement ofthe C-clamp.

13. A device as set forth in claim 1 wherein the C- clamp has a clampingscrew threaded in one end of the C-frame of said clamp and has twoinwardly embossed fiat bearing surfaces on the inner circumference ofthe other end of the C-frame spaced approximately 30 on opposite sidesof a center line extended from said screw, these surfaces being tangentto a circle of a predetermined radius for a spindle small enough toenter between said surfaces and said screw for clamping engagement ofthe C-clamp, there being also a third flat inwardly embossed bearingsurface on the inner circumference of said C- frame tangent to the samecircle as the other two flat bearing surfaces and disposed approximatelyfrom the center line of said screw.

14. A device as set forth in claim 1 wherein the cylindrical radius rodis of a predetermined length but is 7 8 removable and interchangeablewith another cylindrical FOREIGN PATENTS radius rod of a differentlength. 589563 12/1959 Canada References Cited 251,157 7/1948Switzerland.

UNITED STATES PATENTS 5 ROY D FRAZIER, Primary Examiner. 1,059,948 4/1913 Neherle 248284 I. FRANKLIN FOSS, Assistant Examiner. 1,421,4677/1922 Harden 248284 1,680,560 '8/1928 McDonald 248279 X US. Cl. X.R.

Mueller 2,940,783 6/1960 Engelhardt 287-56 10

